Sync. linear drive motor for rail vehicle - varies pole angle to maintain acceleration when supply transformer max. voltage is reached

摘要

The motor has a stator provided as field windings extending along the track and supplied in sections with varying voltages and frequencies. During acceleration the motor current is held constant until the supply transformer max voltage (Umax) is reached, with further acceleration obtained by adjusting the pole angle (lambda b). The voltage drop vector triangle (Us, Ur, Ul) for the field winding is swung through a sufficient angle for the geometric sum of the voltage drop (Us) across the field winding and the supplied main field voltage (Uh) to remain less than the max, voltage (Umax) of the transformer.